Data from: Experimental evolution reveals balancing selection underlying coexistence of alternative male reproductive phenotypes

Heritable alternative reproductive phenotypes (ARPs), which differ in traits associated with competition for mates, occur across taxa. If polymorphism in the genes underlying ARPs is maintained by balancing selection, selection should return ARP proportions to their equilibrium if that equilibrium is perturbed. Here, we used an experimental evolution approach to directly test this prediction in male Rhizoglyphus robini, in which two heritable morphs occur: armoured fighters and more female-like, benign scramblers. Using selection lines nearly fixed for male morph, we constructed replicate populations consisting of 50% or 94% fighters, and allowed them to evolve for 14 generations in two types of environment: simple or spatially complex. We found that in both types of populations, the proportion of fighters converged on values within a narrow range of 0.70-0.83, although the rate of convergence was slower in the complex environment. Our results thus demonstrate balancing selection acting on polymorphism(s) underlying ARPs

可遗传替代性生殖表型（Heritable alternative reproductive phenotypes，ARPs）在配偶竞争相关性状上存在差异，广泛分布于各类生物类群中。若ARPs相关基因的多态性由平衡选择维持，则当该多态性的平衡比例被扰动时，选择应能将ARPs的比例恢复至平衡态。
本研究采用实验进化方法，在罗宾根螨（Rhizoglyphus robini）雄螨中直接验证这一预测：该物种存在两种可遗传的形态型——具装甲的格斗型个体，以及更类似雌性的温和游走型个体。我们利用几乎固定为单一雄螨形态的选择系，构建了格斗型个体占比分别为50%和94%的重复种群，并将其置于简单环境与空间复杂环境两种条件下进化14代。
研究发现，两类环境下的种群中，格斗型个体的占比均收敛至0.70~0.83的狭窄区间内，尽管空间复杂环境中的收敛速率较慢。
综上，本研究结果证实平衡选择作用于维持ARPs相关基因的多态性。